This invention relates to batteries and more particularly to a battery capable of withstanding vibrational forces.
Batteries of one or more electrochemical cells are oftentimes subjected in use to thrusts and vibration along various axes of the battery. Connection junctures between the electrode plate tabs and connecting straps and between the connecting straps and intercell lugs and output terminals are particularly susceptible to stress cracking. Crack initiation and propogation is a problem in various battery systems, including alkaline and acid systems, and particularly in lead-acid batteries where high purity lead straps are especially prone to premature failure when subjected to vibration.
U.S. Pat. No. 4,216,277 to Uba solved his vibration problem by molding protuberant ribs into the lid of the battery housing, the ribs bearing down substantially on the lead strap connection to limit movement thereof. U.S. Pat. No. 3,909,294 to Kosuge et al solved his vibrational problem by incorporation of teeth-shaped holding members bearing down upon the electrode plate groups and positioned intermediate the strap connections of a battery. While undoubtedly helpful in reducing the effects of vibration, the hold down member by virtue of its location will not positively locate the strap members or prevent relative movement between the straps and the housing of the battery.
Another approach to the vibration problem has been to use recessed portions of the battery casing which bear down on separator edges which extend beyond the edges of the plates, disclosed for instance in U.S. Pat. No. 4,346,151 to Uba et al. Other prior art of which Applicant is aware are U.S. Pat. Nos. 2,480,964 to Randall, 2,521,924 to Longaker and 2,702,829 to Chapel.
It is a primary object of this invention to provide a battery which is substantially vibration proof irrespective of the direction of vibrational forces. It is another object to provide a device for a battery serving the dual functions of vibration resistance and electrical insulation.